Oct 4, 2012 7:00pm EDT
've never been captured on film. >> until they followed the brown pelicans to mexico's sea of cort cortez. for every minute you see in the show airing on discovery saturday night, there are ten hours of film that didn't make air. >> i think anything that can fly at some point or another, we've put a camera on it. we made miniature cameras birds could carry. >> four years in the making, they hand raised snow geese and a vulture to fly with cameras for this film. how did they keep it on? >> we developed harnesses. they were so carefully positioned, it didn't disturb their flight. >> downer also used spy cameras hidden in mud or behind faux fla ming os. it took more than 100 days to get this spectacular scene. anne thompson, nbc news, new york. >> spectacular. that's our broadcast on a thursday night. thank you for being here with us and please don't forget "rock center" tonight. it includes matt lauer's interview with mark zuckerberg. we hope to see you back here tomorrow evening. good night.